Yawing structures, including certain fluid turbines, may require the ability to achieve different azimuth headings throughout their deployment. For example, in the case of certain fluid turbines such as tidal turbines, water turbines, or wind turbines, the fluid flow heading is often variable, and the rotor of the turbine needs to be oriented in the proper orientation relative to the flow of the fluid in order for the fluid turbine to efficiently harness power to maximize power production.
Existing solutions that are currently employed as yaw brake mechanisms include disc brakes and motor brakes. Utilization of disc brakes as a yaw braking mechanism follows the same principle as a car's disc brake system, but on a much larger scale. Utilizing disc brakes requires a large number of disc brakes to accommodate the high torque. This results in a heavy, tall, and costly braking mechanism.
Motor brakes employ a low torque brake within the yaw drive powertrain system. The brake's low torque is multiplied by the use of a high gear ratio gearbox to create a large torque at the pinion to slew bearing interface. Using multiple powertrains further increases the braking torque available at the slew bearing.
In addition, it is known to use a single rotor lock mechanism between the rotor hub and nacelle interface of a wind turbine for hub lock out (i.e. prevent rotation of the rotor hub relative to the nacelle) during maintenance.